Dispensing fluid from an infusion pump system

ABSTRACT

Some embodiments of a medical infusion pump system include a pump device having a cap device that mates with a pump housing to retain a medicine cartridge therein. In addition to retaining the medicine cartridge in the pump housing, the cap device may perform a number of preparatory functions or safety functions. In addition or in the alternative, some embodiments of the pump device may include a drive system that advances a piston rod to dispense medicine to the patient in a safe and energy efficient manner.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation of U.S. patent application Ser. No. 13/251,865filed on Oct. 3, 2011, which is a division of U.S. patent applicationSer. No. 11/677,706 filed on Feb. 22, 2007 (now U.S. Pat. No.8,057,436). The contents of these prior applications are fullyincorporated by reference herein.

TECHNICAL FIELD

This document relates to an infusion pump system, such as a medicalinfusion pump system.

BACKGROUND

Pump devices are commonly used to deliver one or more fluids to atargeted individual. For example, a medical infusion pump device may beused to deliver a medicine to a patient as part of a medical treatment.The medicine that is delivered by the infusion pump device can depend onthe condition of the patient and the desired treatment plan. Forexample, infusion pump devices have been used to deliver insulin to thevasculature of diabetes patients so as to regulate blood-glucose levels.

A number of factors may affect the design of infusion pump devices. Onesuch factor is the size of the device. The pump device may be sized tohouse the various pump components, yet a large device may reduce theportability for the user. Another factor that may affect the design ofan infusion pump device is the reservoir that contains the medicine. Forexample, if the reservoir is provided in a sealed form, the seal mayrequire penetration before the medicine is infused to the user. Yetanother factor that can affect the design of the pump device is thedisposability. If, for example, the pump device is to be disposed afterexhaustion (e.g., after a single use or a certain number of uses, aftera particular period of time, or the like), reuse of the exhausted pumpdevice may create a safety risk to the user.

SUMMARY

Some embodiments of a medical infusion pump system include a pump devicehaving a cap device that mates with a pump housing to retain a medicinecartridge therein. In addition to retaining the medicine cartridge inthe pump housing, the cap device may perform one or more functions, suchas forcing the medicine cartridge to secure to a pump drive component,piercing a sealed end of the medicine cartridge to provide a flow pathfor the medicine, priming the plunger in the medicine cartridge with a“break away” force, providing a flow sensor to the medicine flow path,locking the medicine cartridge in the pump housing to promote disposalof the pump device after the medicine cartridge is exhausted, preventingthe dispensation of medicine if the cap device is improperly engagedwith the pump housing, or a combination thereof.

In addition or in the alternative, some embodiments of the pump devicemay include a drive system that reliably advances a piston rod todispense medicine to the patient. The drive system may employ a springdevice or the like to provide the dispensing drive energy to a ratchetmechanism. Also, the drive system may include an electrically poweredactuator (e.g., a reversible motor) that provides the reset energy tothe ratchet mechanism yet contributes no force on the ratchet mechanismwhen the spring device is delivering the dispensing drive energy. Insuch circumstances, the pump device can reliably and accurately dispensedosages of medicine in a safe and energy efficient manner.

In some embodiments, an infusion pump device may include a pump housingthat defines a space to receive a medicine. The infusion pump device mayalso include a drive system to dispense a medicine from the pump housingwhen the medicine is received in the space. The drive system may includea ratchet mechanism that advances a piston rod during a drive step todispense the medicine when the medicine is received in the space. Also,the drive system may include an electrically powered actuator thatdecouples from the ratchet mechanism during the drive step.

Particular embodiments of an infusion pump device may include a pumphousing that defines a space to receive a medicine. The infusion pumpdevice may also include a drive system to dispense a medicine from thepump housing when the medicine is received in the space. The drivesystem may include a drive wheel that rotates to advance a piston rodtoward the medicine to dispense the medicine when the medicine isreceived in the space. The drive system may further include a ratchetwheel that is incrementally rotated in a forward direction to rotate thedrive wheel and thereby advance the piston rod. The drive system mayalso include a movable pawl that engages the ratchet wheel. The movablepawl may be adjustable from a reset position to a forward position so asto incrementally rotate the ratchet wheel in the forward direction. Thedrive system may further include a spring device that urges the movablepawl to adjust from the reset position to the forward position. Also,the drive system may include an actuator assembly that acts upon themovable pawl to force the movable pawl to the reset position and thatreverses to separate from the movable pawl when the spring deviceadjusts the movable pawl from the reset position to the forwardposition.

Some embodiments may include a method of dispensing medicine from aninfusion pump device. The method may include resetting a ratchetmechanism in a drive system of an infusion pump device by activating anelectrically powered actuator to provide a reset force to a ratchetmechanism. The method may further include driving the ratchet mechanismin a forward direction to advance a piston rod during a drive step so asto dispense a medicine from the infusion pump device. The electricallypowered actuator may be decoupled from the ratchet mechanism during thedrive step.

Some or all of the embodiments may provide one or more of the followingadvantages. First, the pump device may be attached to a controllerdevice so that a user can readily monitor infusion pump operation bysimply viewing a user interface connected to the pump device. In thesecircumstances, the user may activate and control the pump device withoutthe requirement of locating and operating a separate monitoring module.

Second, the infusion pump system may be configured to be portable,wearable, and (in some circumstances) concealable. For example, a usercan conveniently wear the infusion pump system on the user's skin underclothing or can carry the pump device in the user's pocket (or otherportable location) while receiving the medicine dispensed from the pumpdevice.

Third, a number of preparatory functions can be accomplished while theuser performs the relatively simple task of attaching the cap device tothe pump housing. For example, attachment of the cap device can causethe medicine cartridge to be retained in a cavity of the pump housingand can provide a water-tight seal for cavity. In another example,attachment of the cap device can force the plunger of the medicinecartridge to secure to the piston rod in the pump device. In a furtherexample, attachment of the cap device can cause a sealed end of themedicine cartridge to be pierced and thereby provide a flow path for themedicine. In another example, attachment of the cap device can provide a“break away” force to initiate movement of the plunger in the medicinecartridge.

Fourth, one or more of safety functions can be performed while the userperforms the task of attaching the cap device to the pump housing. Forexample, attachment of the cap device may arrange a flow sensor in themedicine flow path to detect occlusions. In another example, attachmentof the cap device may result in the medicine cartridge being locked inthe pump housing. Such a configuration may be useful, for example, incircumstances in which the pump device is designed to be a “one timeuse” disposable unit. In a further example, if the cap device isimproperly engaged with the pump housing, the dispensation of medicinecan be prevented.

Fifth, some embodiments of the drive system of the pump device canaccurately and incrementally dispense fluid from the pump device in acontrolled manner.

Sixth, the drive system of the pump device can be controlled dispensedosages of medicine in a safe and energy efficient manner. For example,in some embodiments, the motor of the drive system can be decoupled fromthe ratchet mechanism during the drive step. In such a configuration,the motor is not required to draw energy from a battery over an extendedperiod of time (e.g., during the drive step in which the piston rod isadvanced to dispense medicine over a period of time).

The details of one or more embodiments of the invention are set forth inthe accompanying drawings and the description below. Other features,objects, and advantages of the invention will be apparent from thedescription and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective exploded view of an infusion pump system inaccordance with some embodiments.

FIG. 2 is a perspective view of the infusion pump system of FIG. 1.

FIG. 3 is an perspective exploded view of a portion of the infusion pumpsystem of FIG. 1.

FIG. 4 is a perspective exploded view of a cap device of the infusionpump system of FIG. 1, in accordance with some embodiments.

FIG. 5 is a perspective exploded view of the cap device of FIG. 4.

FIG. 6 is a perspective exploded view of the cap device of FIG. 4.

FIGS. 7A-D are cross-sectional views of a portion of the infusion pumpsystem of FIG. 1, in accordance with some embodiments.

FIGS. 8A-B are cross-sectional views of a portion of the infusion pumpsystem of FIG. 1, in accordance with further embodiments.

FIG. 9 is an exploded perspective view of a portion of a pump device ofthe infusion pump system of FIG. 1, in accordance with some embodiments.

FIG. 10 is an exploded perspective view of a piston rod and a medicinecartridge plunger of the pump device of FIG. 9.

FIG. 11 is a perspective view of a plunger engagement device of thepiston rod of FIG. 10.

FIG. 12 is a side view of the piston rod and the medicine cartridgeplunger of FIG. 10.

FIGS. 13A-D are perspective views of a plunger engagement device of apiston rod and a medicine cartridge plunger, in accordance with someembodiments.

FIGS. 14A-B are perspective and axial views of a plunger penetrationmember and a medicine cartridge plunger, in accordance with someembodiments.

FIGS. 15A-B are perspective and axial views of a plunger penetrationmember and a medicine cartridge plunger, in accordance with otherembodiments.

FIGS. 16A-B are perspective and axial views of a plunger penetrationmember and a medicine cartridge plunger, in accordance with furtherembodiments.

FIG. 17 is a side view of a plunger penetration member having aretention portion, in accordance with some embodiments.

FIG. 18 is a side view of a plunger penetration member having aretention portion, in accordance with some embodiments.

FIG. 19 is an axial view of a plunger penetration member and a medicinecartridge plunger, in accordance with particular embodiments.

FIG. 20 is an axial view of plunger penetration members and a medicinecartridge plunger, in accordance with other embodiments.

FIG. 21 is an axial view of plunger penetration members and a medicinecartridge plunger, in accordance with some embodiments.

FIG. 22 is an axial view of plunger penetration members and a medicinecartridge plunger, in accordance with particular embodiments.

FIG. 23 is an axial view of plunger penetration members and a medicinecartridge plunger, in accordance with other embodiments.

FIG. 24 is an axial view of plunger penetration members and a medicinecartridge plunger, in accordance with some embodiments.

FIG. 25 is cross-sectional side view of plunger engagement device of apiston rod and a medicine cartridge plunger, in accordance with someembodiments.

FIG. 26 is perspective view of a pump device, with some portions removedto view a drive system.

FIG. 27 is a perspective view of the drive system of the pump device ofFIG. 26, in accordance with some embodiments.

FIG. 28 is another perspective view of the drive system of FIG. 27 in afirst position.

FIG. 29 is a perspective view of the drive system of FIG. 27 in a secondposition.

FIG. 30 is a perspective view of the drive system of FIG. 27 whilereturning to the first position.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Referring to FIG. 1, an infusion pump system 10 can include a pumpdevice 100 and a controller device 200 that communicates with the pumpdevice 100. The pump device 100 includes a housing structure 110 thatdefines a cavity 116 in which a fluid cartridge 120 can be received. Thepump device 100 also includes a cap device 130 to retain the fluidcartridge 120 in the cavity 116 of the housing structure 110. The pumpdevice 100 includes a drive system (described in more detail below) thatadvances a plunger 125 in the fluid cartridge 120 so as to dispensefluid therefrom. The controller device 200 communicates with the pumpdevice 100 to control the operation of the drive system. When thecontroller device 200, the pump device 100 (including the cap device130), and the fluid cartridge 120 are assembled together, the user can(in some embodiments) conveniently wear the infusion pump system 10 onthe user's skin under clothing or in the user's pocket while receivingthe fluid dispensed from the pump device 100.

The controller device 200 may be configured as a reusable component thatprovides electronics and a user interface to control the operation ofthe pump device 100. In such circumstances, the pump device 100 can be adisposable component that is disposed of after a single use. Forexample, the pump device 100 can be a “one time use” component that isthrown away after the fluid cartridge 120 therein is exhausted.Thereafter, the user can removably attach a new pump device 100 to thereusable controller device 200 for the dispensation of fluid from a newfluid cartridge 120. Accordingly, the user is permitted to reuse thecontroller device 200 (which may include complex or valuableelectronics) while disposing of the relatively low-cost pump device 100after each use. Such a pump system 10 can provide enhanced user safetyas a new pump device 100 (and drive system therein) is employed witheach new fluid cartridge 120.

In use, the cap device 130 is coupled to the pump housing 110 to retainthe fluid cartridge 120 in the cavity 116 of the pump device 100, andthe pump device 100 (with the fluid cartridge therein) is removablyattached to the controller device 200. The cap device 130 may bemultifunctional in that it performs a number of functions for the pumpdevice operation. For example, in some embodiments, attachment of thecap device 130 may cause one or more of the following preparatoryfunctions: forcing the plunger 125 of the fluid cartridge 120 to secureto a piston rod (described in connection with FIG. 7B), piercing aseptum 121 of the fluid cartridge 120 to provide a flow path for thefluid (described in connection with FIG. 7C), and priming the fluidcartridge 120 with a “break away” force to initiate movement of theplunger 125 in the fluid cartridge 120 (described in connection withFIG. 7D). In addition or in the alternative, attachment of the capdevice 130 may also cause one or more of the following safety relatedfunctions: aligning a flow sensor with the fluid flow path (described inconnection with FIGS. 8A-B), locking the fluid cartridge 120 in the pumphousing 110 to thereby promote disposal of the pump device 100 afterexhaustion (described in connection with FIGS. 8A-B), and ceasing orpreventing the dispensation of fluid if the cap device 130 is improperlyengaged with the pump housing 110 (described in connection with FIGS.8A-B).

In addition, the drive system of the pump device 100 may have a designthat enables the dispensing of fluid in a safe and energy efficientmanner. As described in more detail below in connection with FIGS.26-30, the piston rod can be advanced incrementally using pawl andratchet techniques. For each incremental advancement of the piston rod,there is a reset step and a drive step. In the reset step, anelectrically powered component forces a pawl to move in a firstdirection and to engage another tooth of a ratchet wheel. Then, when thepawl is engaged on the next tooth of the ratchet wheel, the drive stepbegins in which the electrically powered component decouples from thepawl (e.g., the electrically powered actuator assembly separates fromthe pawl). This allows a spring device that is attached to the pawl tomove the pawl in the opposite direction, thereby causing the ratchetwheel to turn an incremental amount. A gear system translates theincremental rotation of the ratchet wheel into incremental advancementof the piston rod. Among other advantages, such embodiments of the drivesystem help to reduce the overall time that the electrical power isdrawn from a battery, which may facilitate a reduction in batteryrequirements. In addition, the release of medicine from the cartridge,which occurs during the drive step, is caused only by the force appliedby the spring, and thus is consistent and repeatable. Examples of suchdrive systems are described in more detail below in connection withFIGS. 26-30.

Still referring to FIG. 1, in this embodiment, the pump system 10 is amedical infusion pump system that is configured to controllably dispensea medicine from the cartridge 120. As such, the fluid cartridge 120 maycontain a medicine 126 to be infused into the tissue or vasculature of atargeted individual, such as a human or animal patient. For example, thepump device 100 can be adapted to receive a medicine cartridge 120 inthe form of a carpule that is preloaded with insulin or another medicinefor use in the treatment of Diabetes (e.g., Byetta®, Symlin®, orothers). Such a cartridge 120 may be supplied, for example, by Eli Lillyand Co. of Indianapolis, Ind. Other examples of medicines contained inthe fluid cartridge 120 include: pain relief drugs, hormone therapy,blood pressure treatments, anti-emetics, osteoporosis treatments, orother injectable medicines. The fluid cartridge 120 may have otherconfigurations. For example, the pump housing structure 110 may includeone or more walls that surround a plunger to define a reservoir in whichthe medicine is injected or otherwise received.

In some embodiments, the controller device 200 may be removably attachedto the pump device 100 so that the two components are mechanicallymounted to one another in a fixed relationship. Such a mechanicalmounting can form an electrical connection between the removablecontroller device 200 and the pump device 100. For example, thecontroller device 200 may be in electrical communication with a portionof a drive system (not shown in FIG. 1) of the pump device 100. Asdescribed in more detail below, the pump device 100 includes a drivesystem that causes controlled dispensation of the medicine or otherfluid from the cartridge 120. In some embodiments, the drive systemincrementally advances a piston rod (not shown in FIG. 1) longitudinallyinto the cartridge 120 so that the fluid is forced out of an output end122. A septum 121 at the output end 122 of the fluid cartridge 122 canbe pierced to permit fluid outflow when the cap device 130 is connectedto the pump housing structure 110 (described in more detail below).Thus, when the pump device 100 and the controller device 200 areattached and thereby electrically connected, the controller device 200communicates electronic control signals via a hard-wire-connection(e.g., electrical contacts or the like) to the drive system or othercomponents of the pump device 100. In response to the electrical controlsignals from the controller device 200, the drive system of the pumpdevice 100 causes medicine to incrementally dispense from the medicinecartridge 120.

Still referring to FIG. 1, the controller device 200 includes acontroller housing structure 210 that is configured to mate with acomplementary portion of the pump housing structure 110 so as to form areleasable mechanical connection. For example, the controller housingstructure 210 may define a cavity 215 that mates with a portion of thepump housing structure 110 for a snap fit engagement (as shown, forexample, in FIG. 2). Also, the controller housing structure 210 mayinclude a tab 212 that engages a mating surface 117 of the pump housingstructure 110 when the controller device 200 is removably attached tothe pump device 100. In some embodiments, a magnetic attachment may beemployed to releasably secure the pump device 100 to the controllerdevice 200. For example, the magnetic attachment can serve to retain thepump housing structure 110 in the cavity 215 defined by the controllerhousing structure 210. In alternative embodiments, one or morereleasable connector devices (e.g., mating tongues and grooves, mountingprotrusions friction fit into mating cavities, or the like) can be usedto further implement the releasable attachment of the controller device200 to the pump device 100.

As shown in FIG. 1, the pump device 100 may include one or moreelectrical contacts 118 (e.g., conductive pads, pins, and the like) thatare exposed to the controller device 200 and that mate withcomplementary electrical contacts (not show in FIG. 1) on the adjacentface of the controller device 200. The electrical contacts 118 providethe electrical communication between the control circuitry (e.g., one ormore circuits including a microprocessor or the like and memory) housedin the controller device 200 and at least a portion of the drive systemor other components of the pump device 100. For example, in someembodiments, the electrical contacts permit the transmission ofelectrical control signals to the pump device 100 and the reception offeedback signals (e.g., sensor signals) from particular componentswithin the pump device 100. Previously incorporated U.S. patentapplication Ser. No. 11/522,603 describes further embodiments of acontroller device that can be attached to and communicate with a pumpdevice.

Still referring to FIG. 1, the controller device 200 includes a userinterface 220 that permits a user to monitor the operation of the pumpdevice 100. In some embodiments, the user interface includes a display222 and one or more user-selectable buttons (e.g., four buttons 224 a,224 b, 224 c, and 224 d in this embodiment). The display 222 may includean active area 223 in which numerals, text, symbols, images, orcombination thereof can be displayed. For example, the display 222 maybe used to communicate a number of settings or menu options for theinfusion pump system 10. In this embodiment, the user may press one ormore of the buttons 224 a, 224 b, 224 c, and 224 d to shuffle through anumber of menus or program screens that show particular settings anddata (e.g., review data that shows the medicine dispensing rate, thetotal amount of medicine dispensed in a given time period, the amount ofmedicine scheduled to be dispensed at a particular time or date, theapproximate amount of medicine remaining in the cartridge 120, or thelike). In some embodiments, the user can adjust the settings orotherwise program the controller device 200 by pressing one or morebuttons 224 a, 224 b, 224 c, and 224 d of the user interface 220. Forexample, in embodiments of the infusion pump system 10 configured todispense insulin, the user may press one or more of the buttons 224 a,224 b, 224 c, and 224 d to change the dispensation rate of insulin or torequest that a bolus of insulin be dispensed immediately or at ascheduled, later time.

The display 222 of the user interface 220 may be configured to displayquick reference information when no buttons 224 a, 224 b, 224 c, and 224d have been pressed. In this example, the active area 223 of the display222 can display the time and the date for a period of time after nobutton 224 a, 224 b, 224 c, and 224 d has been actuated (e.g., fiveseconds, 10 seconds, 30 seconds, 1 minute, 5 minutes, or the like).Thereafter, the display 222 may enter sleep mode in which the activearea 223 is blank, thereby conserving battery power. In addition or inthe alternative, the active area can display particular device settings,such as the current dispensation rate or the total medicine dispensed,for a period of time after no button 224 a, 224 b, 224 c, or 224 d hasbeen actuated (e.g., five seconds, 10 seconds, 30 seconds, 1 minute, 5minutes, or the like). Again, thereafter the display 222 may enter sleepmode to conserve battery power. In certain embodiments, the display 222can dim after a first period of time in which no button 224 a, 224 b,224 c, or 224 d has been actuated (e.g., after 15 seconds or the like),and then the display 22 can enter sleep mode and become blank after asecond period of time in which no button 224 a, 224 b, 224 c, or 224 dhas been actuated (e.g., after 30 seconds or the like). Thus, thedimming of the display device 222 can alert a user viewing the displaydevice 222 when the active area 223 of the display device will soonbecome blank.

Accordingly, when the controller device 200 is connected to the pumpdevice 100, the user is provided with the opportunity to readily monitorinfusion pump operation by simply viewing the user interface 220connected to the pump device 100. Such monitoring capabilities mayprovide comfort to a user who may have urgent questions about thecurrent operation of the pump device 100 (e.g., the user may be unableto receive immediate answers if wearing an infusion pump device havingno user interface attached thereto).

Also, in these embodiments, there may be no need for the user to carryand operate a separate module to monitor the operation of the infusionpump device 100, thereby simplifying the monitoring process and reducingthe number of devices that must be carried by the user. If a need arisesin which the user desires to monitor the operation of the pump device100 or to adjust settings of the pump system 10 (e.g., to request abolus amount of medicine), the user can readily operate the userinterface 220 removably attached to the pump device 100, without therequirement of locating and operating a separate monitoring module.

In other embodiments, the user interface 200 is not limited to thedisplay and buttons depicted in FIG. 1. For example, in someembodiments, the user interface 220 may include only one button or mayinclude a greater numbers of buttons, such as three buttons, fourbuttons, five buttons, or more. In another example, the user interface220 of the controller device 200 may include a touch screen so that auser may select buttons defined by the active area of the touch screendisplay. Alternatively, the user interface 220 may comprise audio inputsor outputs so that a user can monitor the operation of the pump device100.

Referring to FIG. 2, the infusion pump system 10 may be configured to beportable and can be wearable and concealable. For example, a user canconveniently wear the infusion pump system 10 on the user's skin (e.g.,skin adhesive) underneath the user's clothing or carry the pump device100 in the user's pocket (or other portable location) while receivingthe medicine dispensed from the pump device 100. As described below inconnection with FIGS. 26-30, the drive system may be housed in thehousing structure 110 of the pump device 100 in a compact manner so thatthe pump device 100 has a reduced length. For example, in thecircumstances in which the medicine cartridge 120 has a length of about6 cm to about 7 cm (about 6.4 cm in one embodiment), the overall lengthof the pump housing structure 110 (which contains medicine cartridge andthe drive system) can be about 7 cm to about 9 cm (about 8.3 cm or lessin one embodiment). In addition, the pump housing structure 110 may havean overall height of about 1.5 cm to about 4 cm (about 2.9 cm or less inone embodiment) and an overall thickness of about 8 mm to about 20 mm(about 14.5 mm or less in one embodiment). In such circumstances, thecontroller device 200 can be figured to mate with the pump housing 110so that, when removably attached to one another, the components define aportable infusion pump unit that stores a relatively large quantity ofmedicine compared to the overall size of the unit. For example, in thisembodiment, the infusion pump system 10 (including the pump device 100attached to the removable controller device 200) may have an overalllength of about 7 cm to about 9 cm (about 8.5 cm or less in oneembodiment), an overall height of about 1.5 cm to about 4 cm (about 3.5cm or less in one embodiment), and an overall thickness of about 8 mm toabout 20 mm (about 15 mm or less in one embodiment).

The pump system 10 is shown in FIG. 2 as being held in a user's hand soas to illustrate an exemplary size of the system 10. As shown, thisembodiment of the infusion pump system 10 is pocket-sized so that thepump device 100 and controller device 200 can be worn in the user'spocket or in another portion of the user's clothing. In suchembodiments, the cap device 130 of the pump device 100 may be configuredto mate with an infusion set 127. In general, the infusion set 127 istubing system that connects the infusion pump device 100 to the user(e.g., to deliver medicine into the vasculature under the user's skin).The infusion set 127 may include a connector 128 (e.g., a luerconnector), a flexible tube 129 that extends from the connector 128 to asubcutaneous cannula (not shown in FIG. 2), and a skin adhesive patch(not shown in FIG. 2) that secures the subcutaneous cannula to theinfusion site. The skin adhesive patch can retain the infusion cannulain fluid communication with the tissue or vasculature of the patient sothat the medicine dispensed through the tube 129 passes through thecannula and into the user's body. The cap device 130 may provide fluidcommunication between the output end 122 (FIG. 1) of the medicinecartridge 120 and the tube 129 of the infusion set 127. In theseembodiments, the user can carry the portable infusion pump system 10(e.g., in the user's pocket, connected to a belt clip, adhered to theuser's skin, or the like) while the tube 129 extends to the location inwhich the skin is penetrated for infusion. If the user desires tomonitor the operation of the pump device 100 or to adjust the settingsof the infusion pump system 10, the user can readily access the userinterface 220 of the controller device 200 without the need for carryingand operating a separate module.

In other embodiments, the infusion pump system 10 may be configured toadhere to the user's skin directly at the location in which the skin ispenetrated for medicine infusion. For example, a rear surface 102(FIG. 1) of the pump device 100 may include a skin adhesive patch sothat the pump device 100 is physically adhered to the skin of the userat a particular location. In these embodiments, the cap device 130 mayhave a configuration in which medicine passes directly from the capdevice 130 into an infusion cannula that is penetrated into the user'sskin. In one example, the fluid output port through the cap device 130may include a curve or a 90° corner so that the medicine flow pathextends longitudinally out of the medicine cartridge and then laterallytoward the patient's skin. Again, if the user desires to monitor theoperation of the pump device 100 or to adjust the settings of theinfusion pump system 10, the user can readily access the user interface220 of the controller device 200 without the need for carrying andoperating a second, separate device. For example, the user may looktoward the pump device 100 to view the user interface 220 of thecontroller device 220 that is removably attached thereto.

Referring now to FIG. 3, the cap device 130 may include a number ofcomponents that permit the cap device 130 to mate with the pump housing110 and to interact with the medicine cartridge 120. For example, inthis embodiment, the cap device comprises a slider component 132, androtator component 134, and a fluid path component 136 that can beassembled together. The fluid path component 136 may include needlepenetrator 139 (shown, for example, in FIG. 4) that is advanced throughthe septum 121 of the cartridge 120 when the cap device 130 is receivedby the pump housing 110. The needle penetrator 139 may comprise a hollowneedle device that provides fluid communication with an output port 135of the fluid path component 136. The output port 135 is capable ofdirecting the fluid toward the infusion set tubing 129 (FIG. 2) when theinfusion set connector 128 (FIG. 2) is joined with the cap device 130.In this embodiment, the infusion set connector 128 (FIG. 2) is a luerconnector that mates with a threaded cavity 138 of the fluid pathcomponent 136. As such, the luer connector can be secured into thethreaded cavity 138 so that the output port 135 comes into fluidcommunication with the infusion set tubing 129 (FIG. 2).

Still referring to FIG. 3, one or more components of the cap device 130may engage the portion of the pump housing 110 that defines the cavity116 in which the medicine cartridge 120 is received. For example, inthis embodiment, the slider component 132 includes a first set ofprotrusions 131 that slidably mate with longitudinal slots 111 form inthe interior wall of the pump housing 110. Likewise, the rotatorcomponent 134 includes a second set of protrusions 133 that alsoslidably mate with the longitudinal slots 111. Accordingly, the capdevice 130 can be advanced into the cavity 116 of the pump housing 110when the protrusions 131 and 133 are aligned with longitudinal slots 111of the pump housing 110. Such a configuration provides for guidance ofthe cap device 130 as the cap device is advanced toward the medicinecartridge 120 received in the cavity 116.

After the cap device 130 is advanced into the cavity a particulardistance, the second set of protrusions 133 on the rotator component 134may align with circumferential slots 113 that extend from thelongitudinal slots 111. For example, in this embodiment, the cap device130 can be advanced into the cavity 116 toward the medicine cartridge120 until a rim 144 of the rotator component 134 reaches the end face ofthe pump housing 110. At this point, the protrusions 133 on the rotatorcomponent 134 align with the circumferential slots 113, therebypermitting the rotator component 134 to rotate relative to the pumphousing 110 (e.g., the protrusions 133 can slide circumferentiallywithin the circumferential slots 113). Although the rotator component134 of the cap device 130 is permitted to rotate relative to the pumphousing 110, the protrusions 131 of the slider component 132 remainengaged with the longitudinal slots 111, thereby permitting the slidercomponent to slide in an axial direction relative to the pump housing(but hindering rotation of the slider component 132 relative to the pumphousing 110).

As described in more detail below, the relative movement of thecomponents of the cap device 130 (e.g., rotation of the rotatorcomponent 134 and longitudinal advancement of the slider component 132)enables a user to perform a number of functions by merely attaching ofthe cap device 130 to the pump housing 110. For example, such functionsmay include one or more of the following: forcing the medicine cartridge120 to secure to a portion of a piston rod 370 (described in connectionwith FIGS. 7A-D and 10-25), piercing the septum 121 of the medicinecartridge 120 to provide a flow path for the medicine (described inconnection with FIGS. 7A-D), priming the medicine cartridge 120 with a“break away” force to initiate movement of the plunger 125 in themedicine cartridge 120 (described in connections with FIGS. 7A-D),providing the a flow sensor 165 to the medicine flow path (described inconnection with FIGS. 8A-B), locking the medicine cartridge 120 in thepump housing 110 to thereby promote disposal of the pump device 100after exhaustion (described in connection with FIGS. 8A-B), and ceasingor preventing the dispensation of medicine if the cap device 130 isimproperly engaged with the pump housing 110 (described in connectionwith FIGS. 8A-B).

Referring now to FIGS. 4-6, the cap device 130 can be assembled topermit relative movement of the components 132, 134, and 136. In thisembodiment, the slider component 132, the rotator component 134 and thefluid path component 136 are assembled to one another along alongitudinal axis 150. The slider component 132 is configured torotatably engage the rotator component 134. For example, in thisembodiment, the slider component 132 includes external cylindricalsurfaces 151 that mate with an internal bore 152 of the rotatorcomponent 134. As such, the rotator component 134 can rotate relative tothe slider component 132.

In addition, the slider component 132 is configured to slidably engagethe fluid path component 136. For example, in this embodiment, theslider component 132 includes opposing flat surfaces 153 that mate withcomplementary flat surfaces 154 of the fluid path component 136. Thisconfiguration permits the fluid path component 136 to movelongitudinally along the axis 150 toward the slider component 132. Whenthe shoulder surfaces 156 of the fluid path component 136 abut againstthe forward faces 155 of the slider component 132, the longitudinalmovement of the fluid path component 136 can cause similar movement ofthe slider component 132. Also, this configuration permits the fluidpath component 136 to remain rotationally fixed relative to the slidercomponent 132. For example, the fluid path component 136 remainsrotationally stationary when the slider component 132 is retained in arotationally stationary position (e.g., when the slider componentprotrusions 131 are mated with the longitudinal slots 111 of the pumphousing 110 (FIG. 3)). As such, the slider component 132 and the fluidpath component 136 can remain rotationally stationary relative to thepump housing 110 (FIG. 3) while the rotator component 134 is rotatedrelative to the pump housing 110.

Still referring to FIGS. 4-6, the rotator component 134 may beconfigured to engage the fluid path component 136 such that rotationalmovement of the rotator component 134 causes longitudinal movement ofthe fluid path component 136. For example, in this embodiment, therotator component 134 includes an internal thread pattern 157 that mateswith an external thread pattern 158 of the fluid path component 136. Thethread patterns 157 and 158 mate together when the slider component 132and the fluid path component 136 are arranged at least partially in therotator component 134. Accordingly, when the slider component 132 isretained in a rotationally stationary position (e.g., when the slidercomponent protrusions 131 are mated with the longitudinal slots 111 ofthe pump housing 110 (FIG. 3)), the rotator component 134 can rotaterelative thereto and thereby cause the longitudinal movement of thefluid path component 136. In these circumstances, the engagement of theflat surfaces 153 with the complementary flat surfaces 154 prevents thefluid path component 136 from rotating with the rotator component 134,so the thread engagement translates the rotator component's rotationalmovement to the fluid path component's longitudinal movement.

As previously described, the fluid path component 136 includes a needlepenetrator 139 that extends longitudinally to pierce the septum 121 ofthe medicine cartridge 120 (FIG. 3) when the cap device 130 is urgedtoward the medicine cartridge 120. The needle penetrator 139 of thefluid path component 136 is configured to extend through a bore 159(FIGS. 4-6) of the slider component 132 when the cap device 130 isassembled. As such, during engagement of the cap device 130 with thepump housing 110 (FIG. 3), the cap device 130 can be operated topenetrate the medicine cartridge 120 and create a fluid path to theoutput port 135. As described in more detail below, the cap device 130may also be used to perform a number of other functions when the userperforms the relatively simple task of engaging the cap device 130 tothe pump housing 110.

Referring now to FIGS. 7A-D and 8A-B, some embodiments of the cap device130 are capable of performing multiple functions when the cap device 130is being coupled to the pump housing 110. Some of these functions mayinclude preparatory functions and safety functions. For example, in someembodiments, attachment of the cap device 130 may cause one or more ofthe following preparatory functions: retaining the medicine cartridge120 in the cavity 116 of the pump housing 110 (described in connectionwith FIG. 7A), forcing the plunger 125 of the medicine cartridge 120 tosecure to a piston rod (described in connection with FIG. 7B), piercingthe septum 121 of the medicine cartridge 120 to provide a flow path forthe medicine (described in connection with FIG. 7C), and priming themedicine cartridge 120 with a “break away” force to initiate movement ofthe plunger 125 in the medicine cartridge 120 (described in connectionwith FIG. 7D). In addition or in the alternative, attachment of the capdevice 130 may also cause one or more of the following safety relatedfunctions: aligning a flow sensor 165 with the medicine flow path(described in connection with FIGS. 8A-B), locking the medicinecartridge 120 in the pump housing 110 to thereby promote disposal of thepump device 100 after exhaustion (described in connection with FIGS.8A-B), and ceasing or preventing the dispensation of medicine if the capdevice 130 is improperly engaged with the pump housing 110 (described inconnection with FIGS. 8A-B).

Referring to now FIG. 7A, the cap device 130 can be coupled to the pumpdevice 100 so as to retain the medicine cartridge 120 in the cavity 116of the pump housing 110. In this embodiment, the medicine cartridge 120includes a cylindrical wall that fits within the cylindrical cavity 116at least partially defined by the pump housing 110. As shown in FIG. 7A,the cap device 130 may approach the pump housing 110 after the medicinecartridge 120 is received in the cavity 116 so that the cap device 130seals the cavity 116 and retains the cartridge 120 therein. For example,the rim 144 of the cap device 130 may include a seal 142 (e.g., anelastomer o-ring seal or the like) that provides a water-tight seal whenthe rim 144 is urged against the front face of the pump housing 110. Thecartridge may be arranged the pump housing 110 so that the septum 121 atthe output end 122 faces toward the cap device 130 when the cap device130 engages the pump housing 110. As such, the plunger 125 of themedicine cartridge 120 is arranged in the cavity 116 to face toward acomponent of the pump drive system, such as a piston rod 370 (asdescribed in more detail below, for example, in connection with FIGS.9-10). In this embodiment, the medicine cartridge 120 comprises aninsulin carpule that is separate from the pump device 100. In suchcircumstances, the medicine cartridge 120 may be inserted into thecavity 116 to rest against a portion of the piston rod 370 (FIG. 10).

Referring to FIG. 7B, during engagement of the cap device 130 to thepump housing 110, a longitudinal force 140 may be applied to themedicine cartridge 120 so a portion of the medicine cartridge 120becomes secured to the piston rod 370 (e.g., the plunger 125 becomessecured to a plunger engagement device 375 of the piston rod 370 asshown in FIG. 10). This longitudinal force 140 may be applied to themedicine cartridge 120 when at least a portion of the cap device 130 isinserted under force from a user into the pump housing 110. For example,in this embodiment, the slider component 132 of the cap device 130includes the first set of protrusions 131 (FIG. 3) that mate with thelongitudinal slots 111 (FIG. 7A) of the pump housing 110 during theguided insertion of the cap device 130 into the cavity 116. During thisinsertion, the slide component 132 includes a shoulder surface 137 thatabuts with the medicine cartridge 120. The insertion force applied bythe user during the attachment of the cap device 130 to the pump housing110 can be translated to a longitudinal force 140. As described in moredetail below in connection with FIGS. 9-10, this longitudinal force 140can be used to secure the medicine cartridge 120 to the piston rod 370or to another component of the drive system. For example, during theattachment of the cap device 130 to the pump housing 110, the slidercomponent 132 may act upon the medicine cartridge 120 to force themedicine cartridge 120 a rearward displacement 145 that drives theplunger 125 (FIG. 10) toward one or more penetration members 376 of theplunger engagement device 375 of the piston rod 370. In suchcircumstances, the penetration members 376 (FIG. 10) penetrate into theplunger 125 of the medicine cartridge 120 and thereby secure themedicine cartridge 120 the piston rod 370 (FIG. 10). A number of furtherembodiments for the plunger engagement device are described in moredetail below in connection with FIGS. 9-25.

Referring to FIG. 7C, when the cap device 130 is inserted longitudinallyinto the cavity 116 to a particular depth, the rim 144 and the seal 142can be urged against the end face of the pump housing 110 to seal themedicine cartridge 120 in the cavity 116. Also, as previously describedin connection with FIG. 3, the second set of protrusions 133 on therotator component 134 may align with the circumferential slots 113 inthe pump housing 110 when the cap device 130 is inserted to thisparticular depth. As such, the rotator component 134 of the cap device130 is rotatable relative to the pump housing 110 (e.g., the protrusions133 can move circumferentially in the circumferential slots 113). Again,as previously described in connection with FIG. 3, the first protrusions131 of the slider component 132 remain in the longitudinal slots 111 ofthe pump housing 110, so the slider component 132 does not rotate withthe rotator component 134. Such relative movement between the rotatorcomponent 134 and the slider component 132 can be used to longitudinallyadvance the fluid path component 136 (and its needle penetrator 139)toward the septum 121 of the medicine cartridge 120.

As shown in FIG. 7C, the rotator component 134 of the cap device 130 canbe moved in a rotational direction 146 relative to the pump housing 110(which maintains the slider component 132 in a rotational stationaryposition due to the engagement of the first protrusions 131 (FIG. 3) andthe longitudinal slots 111 (FIGS. 3 and 7A)). For example, a user maygrasp the rim 144 of the rotator component 134 and twist it relative tothe pump housing 110 so that the second protrusions 133 (FIG. 3) areguided in the circumferential slots 113 (FIG. 3). Such rotation of therotator component 134 causes the interior thread pattern 157 of therotator component 134 to engage the exterior thread pattern 158 (notshown in FIG. 7C; refer to FIGS. 4-6) of the fluid path component 136.Because the opposing flat surfaces 153 of the slider component 132engage the complementary flat surfaces 154 of the fluid path component136, the fluid path component 136 remains in a rotationally stationaryposition with the slider component 132 (e.g., the rotator component 134also rotates relative to the fluid path component 136). As such, theengagement between the thread patterns 157 (on the rotator component134) and 158 (on the fluid path component 136) cause the rotationalmotion of the rotator component 134 to be translated into a longitudinalmotion for the fluid path component 136. As shown in FIG. 7C, therotation of the rotator component 134 can cause the fluid path component136 to move a longitudinal displacement 147 toward the medicinecartridge 120. This longitudinal displacement 147 results in the needlepenetrator 139 piercing the septum 121 of the medicine cartridge 120 andthereby establishing a fluid path from the medicine cartridge 120 to theoutput port 135 of the fluid path component 136.

In some embodiments in which the attachment of the cap device 130provides the force 140 (FIG. 7B) to cause securement of the medicinecartridge 120 to the piston rod 370 (FIG. 10), this force 140 may beapplied before the needle penetrator 139 penetrates the septum 121 (FIG.7C). Because the septum 121 is not yet pierced during the application ofthe force 140 (FIG. 7B), the force 140 can be used to urge the plunger125 against the plunger engagement device 375 (FIG. 10) withoutnecessarily forcing some portion of the medicine out of the cartridge120.

Referring now to FIG. 7D, attachment of the cap device 130 to the pumphousing 110 can also provide a “break away” force to initiate movementof the plunger 125 in the medicine cartridge 120. Such a “break away”force may be used prepare the plunger 125 for future incrementaldisplacements caused by the drive system. For example, as shown in FIG.1, the plunger 125 is arranged in the medicine cartridge 120 as to actupon the medicine 126 therein. The “break away” force that is requiredto initially move the plunger 125 for the first time may besubstantially greater than the operational drive force required toadvance the plunger 125 yet another increment toward the output end 122of the medicine cartridge 120. In this embodiment, the “break away”force can be provided during the attachment of the cap device 130 to thepump body 110, (rather than by activating the drive system to initiatemovement of the plunger 125 for the first time). Accordingly, drivesystem can provide the operational drive force that (during normaloperation) advances the plunger 125 in subsequent increments toward theoutput end 122 of the medicine cartridge 120, and the user's action(during attachment of the cap device 130) can provide the generallygreater “break away” force to initiate movement of the plunger 125 forthe first time.

Still referring to FIG. 7D, the rotator component 134 of the cap device130 can be moved in the rotational direction 146 relative to the pumphousing 110, for example, by twisting the rim 144 relative to the pumphousing 110. As previously described in connection with FIG. 7C, suchrotation of the rotator component 134 can be translated into alongitudinal motion for the fluid path component 136. After a particularamount of longitudinal advancement of the fluid path component 136, theshoulder surfaces 156 of the fluid path component 136 abut against theforward faces 155 of the slider component 132 (refer also to FIGS. 4-6).Accordingly, the continued longitudinal movement of the fluid pathcomponent 136 (due to the rotation 146 of the rotator component 134)further causes a longitudinal displacement 148 of the slider component132. As previously described in connection with FIG. 7B, the slidercomponent 132 includes a shoulder surface 137 that acts upon themedicine cartridge 120, so the longitudinal displacement 148 of theslider component 132 causes the medicine cartridge 120 to likewise movein the rearward longitudinal direction. Because the plunger 125 (FIG.10) is already engaged with the piston rod 370 (FIG. 10) as previouslydescribed in connection with FIG. 7B, the plunger 125 does not share inthis rearward longitudinal movement. Instead, a break away force 149 isapplied to the medicine cartridge 120 relative to the plunger 125 (whichis maintained in its position due to the piston rod engagement), therebycausing the initial movement of the plunger 125 in the medicinecartridge 120 for the first time.

It should be understood from the description herein that this initialbreak away movement of the plunger 125 in the medicine cartridge 120 maycause a small amount of medicine to be dispensed. However, the infusionset connector 128 (FIG. 2) can be joined with the threaded cavity 138 ofthe fluid path component 136 before the break away force 149 is appliedand (in some embodiments) before the cap device 130 is advanced towardthe medicine cartridge 120 to create the fluid output path. As such, therelatively small amount of medicine dispensed during the initial “breakaway” movement of the plunger 125 in the medicine cartridge 120 may bedispensed through the output port 135 and into the infusion set tubing129 (FIG. 2) to at least partially prime the tubing 129. The pump device100 may be controlled to perform a subsequent priming operation to fullyprime the remaining portion of the infusion set tubing 129.

Accordingly, a number of functions can be performed when the cap device130 is being coupled to the pump housing 110. Some of these functionsmay include initialization and preparatory functions, including but notlimited to: retaining the medicine cartridge 120 in the cavity 116 ofthe pump housing 110 (described in connection with FIG. 7A), providing awater-tight seal for the cavity 116 of the pump housing 110 (describedin connection with FIGS. 7A and 7C), forcing the plunger 125 of themedicine cartridge 120 to secure to a piston rod (described inconnection with FIG. 7B), piercing the septum 121 of the medicinecartridge 120 to provide a flow path for the medicine (described inconnection with FIG. 7C), and providing a “break away” force to initiatemovement of the plunger 125 in the medicine cartridge 120 (described inconnection with FIG. 7D).

Referring now to FIGS. 8A-B, in some embodiments, the process ofcoupling the cap device 130 to the pump housing 110 may result in anumber of safety related functions also being performed. For example,attachment of the cap device 130 to the pump housing can cause themedicine cartridge 120 to be “locked” in the pump housing 110, therebyencouraging disposal of the pump device 100 after exhaustion of themedicine cartridge. As shown in FIGS. 8A-B, a portion of the cap device130 may include locking tabs 161 that mate with corresponding notches162 in the pump housing 110 when the cap device 130 is received by thepump housing 110 at a particular depth. In this embodiment, the lockingtabs 161 are formed as part of the slider component 132 of the device130 so that the tabs 161 are spring biased to extend outwardly. As such,when the slider component 132 is advanced into the cavity 116 (FIG. 3)of the pump housing 110, the locking tabs 161 adjust inwardly toward thelongitudinal axis of the slider component 132 (refer, for example, toFIG. 8A). When the locking tabs 161 reach the corresponding notches 162in the wall of pump housing 110, the locking tabs 161 adjust outwardlyinto the notches 162 (refer, for example to FIG. 8B). In thisembodiment, the locking tabs 161 may be advanced to reach thecorresponding notches 162 in when the longitudinal movement of the fluidpath component 136 (due to the rotation 146 of the rotator component134) further causes the longitudinal displacement 148 of the slidercomponent 132, as previously described in connection with FIG. 7D.

Due to the engagement of the locking tabs 161 in the notches 162, theslider component 132 of the cap device 130 is retained in the pumphousing 110 in a manner that hinders removal of the medicine cartridge120. Accordingly, the cap device 130 can be secured to the pump housing110 in a manner that encourages disposal of the pump device 100 afterexhaustion of the medicine cartridge 120. Such a configuration may beuseful, for example, in circumstances in which the pump device 100 isdesigned to be a “one time use” disposable unit. Thus, the cap device130 may facilitate a “one time use” disposable pump device, therebyreducing the likelihood of failure due to non-intended repeated use ofthe disposable pump device.

It should be understood from the description herein that, in otherembodiments, the locking tabs 161 may be arranged on other components ofthe cap device 130, such as the rotator component 134 or the fluid pathcomponent 136. Also, in other embodiments, the locking mechanism may bein a form other than the locking tabs 161 and corresponding notches 162.For example, the locking mechanism may include an adhesive engagementthat prevents removal of the cap device 130 after attachment to the pumphousing 110, a unidirectional thread pattern that permits tightening buthinders loosening, or the like.

In another example of a safety related function, if the cap device 130is improperly engaged with the pump housing 110, the medicinedispensation can be shutdown. As shown in FIGS. 8A-B, the cap device 130may be used to close a circuit loop that indicates when the cap deviceis engaged with the pump housing 110 in a particular position. In thisembodiment, the circuit loop includes a first conductive line 163 a anda second conductive line 163 b that extend along the pump housing 110and are separated by a gap in the previously described notch 162. Thegap between the first and second conductive lines 163 a-b creates abreak in the sensor circuit that can be closed when the locking tabs 161reach the corresponding notches 162 in the wall of pump housing 110. Inthis embodiment, one of the locking tabs 161 can be used to close thecircuit loop due to a conductive pad 164 disposed on the outer surfaceof the locking tab. When the locking tab 161 is adjusted to mate withthe corresponding notch 162 (as previously described), the electricalcircuit through the first line 163 a, the conductive pad 164, and thesecond line 163 b can be closed, thereby indicating that the cap device130 is properly engaged with the pump housing 110 at a particular depth.The electrical circuit that includes the conductive lines 163 a-b may bea part of (or communicate with) a sensor circuit arranged within thepump device 100 (FIG. 1) or within the removable controller 200 (FIG.1).

Accordingly, if the cap device 130 is secured with the pump housing 110in a proper manner, the controller device 200 may be operated todispense medicine from the medicine cartridge 120. If, however, the capdevice 130 is improperly oriented or becomes dislodged relative to thepump housing 110, the electrical circuit loop (e.g., through the firstline 163 a, the conductive pad 164, and the second line 163 b) maybecome open to indicate such a misalignment to the controller device 200(FIG. 1). In response to such an indication, the controller device 200may prevent medicine dispensation (e.g., cease activation of the drivesystem) and communicate an alarm to the user. Such a configurationpermits the user with an opportunity to correctly attach the cap device130 to the pump housing 110 and thereafter restart safe dispensation ofthe medicine.

It should be understood from the description herein that, in otherembodiments, the electrical circuit loop (e.g., through the first line163 a, the conductive pad 164, and the second line 163 b) may bearranged on other components of the cap device 130, such as the rotatorcomponent 134 or the fluid path component 136. Also, in someembodiments, other devices can be used to detect the proper attachmentof the cap device 130 to the pump housing 110. For example, the capdevice 130 may be used to actuate a position sensor that indicates whenthe cap device is engaged with the pump housing 110 in a particularposition. Alternatively, an optical sensor can be used in combinationwith a light emitted from the controller device 200 (FIG. 1) to indicatewhen the cap device 130 is engaged with the pump housing 110 in aparticular position.

In yet another example of a safety related function, attachment of thecap device 130 to the pump housing 110 can cause a flow sensor to bearranged along the medicine flow path to detect the flow (or nonflow) ofmedicine from the pump device 100. As shown in FIGS. 8A-B, the capdevice 130 may house at least a portion of a flow sensor 165 that isconfigured to detect the flow of medicine through the cap device 130 orto detect an occlusion in the fluid path. In this embodiment, the flowsensor 165 may be arranged within or adjacent to a bypass fluid path166. A portion of the medicine that is dispensed from the medicinecartridge 120 may be redirected through the bypass fluid path 166 fordetection by the flow sensor 165. The bypass fluid path 166 has anoutlet that is in communication with the output port 135 of the capdevice 130. In some embodiments, the bypass fluid path 166 may have asubstantially smaller diameter than the primary fluid path between theneedle penetrator 139 and the output port 135.

The flow sensor 165 may be used to detect when an occlusion exists inthe fluid path between the medicine cartridge 120 and the infusion siteon the user's skin. Such an occlusion may occur, for example, when theinfusion set tubing 129 (FIG. 2) is kinked. If the medicine dispensationpath to the user is occluded, the user may receive no dosage or a lowerdosage of the medicine. As such, the flow sensor 165 housed in the capdevice 130 can be used to indicate when the fluid is flowing or notflowing, thereby permitting the controller device 200 (FIG. 1) tocommunicate an alarm to the user if an occlusion exist.

In some embodiments, the flow sensor 165 housed at least partially inthe cap device 130 may include electrodes 165 a and 165 b that arearranged to detect fluid flow through the bypass fluid path 166. Forexample, an AC current may be passed through the fluid between theelectrodes 165 a-b, and the electrodes 165 a-b can be configured tosense the electrical admittance (e.g., the inverse of the electricalimpedance) through the fluid in the bypass fluid path 166. Theelectrical admittance sensed using the electrodes 165 a and 165 b can becorrelated to a fluid velocity (e.g., a change in the flow speed causesa change in the electrical admittance). In such embodiments, thecontroller device 200 (FIG. 1) may be programmed to correlate the fluidvelocity from the electrical admittance sensed using the electrodes 165a and 165 b. If the fluid velocity falls below a threshold value, thecontroller device 200 may communicate an alarm to the user that anocclusion exists in the fluid path. When the cap device 130 is attachedwith the pump housing 110 in a particular position, the flow sensor 165may be in electrical communication with the controller device 200(FIG. 1) via one or more electrical lines that extend along the pumphousing 110 (refer, for example, to FIG. 8B).

In an alternative embodiment, the flow sensor 165 housed at leastpartially in the cap device 130 may include a pressure sensor thatindicates the fluid pressure in the bypass fluid path 166. For example,a miniature pressure transducer can be arranged in the cap device 130 todetect the fluid pressure. In some cases, the miniature pressuretransducer can be formed as a MEMS (Micro-ElectroMechanical System)device. The miniature pressure transducer may be output an electricalsignal that can be correlated to a fluid pressure value. In suchembodiments, the controller device 200 (FIG. 1) may be programmed tocorrelate the fluid pressure from the signal output by the pressuretransducer. If the fluid pressure increases above a threshold value, thecontroller device 200 may communicate an alarm to the user that anocclusion exists in the fluid path. The fluid passing through the capdevice 130 may act directly upon the pressure transducer, oralternatively, the fluid passing through the cap device may act upon aminiature piston device or diaphragm device that in turn acts upon thepressure transducer.

It should be understood from the description herein that, in alternativeembodiments, other types of flow sensors can operate within the capdevice 130 to detect flow (or nonflow) of the medicine. For example, theflow sensor 165 may include a first probe and a second probe arranged inthe cap device 130—the first probe being used to induce a small oxygen(O₂) concentration into the fluid flow, and the second probe being usedto detect the oxygen level in the fluid flow. If the second probedetects an oxygen concentration greater than a threshold level, thefluid flow may be occluded or partially occluded. As such, thecontroller device 200 may communicate an alarm to the user that anocclusion exists in the fluid path. In another example, the flow sensor165 may include an optical sensor device arranged in a flow path (e.g.,bypass flow path 166) of the cap device 130. The optical sensor mayrespond to a laser light that is emitted from the reusable controllerdevice 200 (FIG. 1) proximate the cap device 130. In some circumstances,the optical sensor device may deform when the fluid pressure increasesabove a threshold level, thereby providing a different response to thelaser light (e.g., reflecting or bending the light in a different mannerthat indicates a fluid pressure greater than the threshold level). Suchdetection of an increased fluid pressure in the cap device 130 canindicate that an occlusion exists in the fluid path, and the controllerdevice 200 the controller device 200 may communicate an alarm to theuser.

Referring now to FIGS. 9-10, the pump device 100 may include a pistonrod 370 that is configured to attach with the medicine cartridge 120.For example, as previously described in connection with FIG. 7B, alongitudinal force 140 may be applied to the medicine cartridge 120during engagement of the cap device 130 to the pump housing 110. Thislongitudinal force 140 can be used to urge a portion of the medicinecartridge 120 (e.g., the plunger 125 in this embodiment) to secure to aplunger engagement device 375 (FIG. 10) of the piston rod 370. In someembodiments, the plunger engagement device 375 may include penetrationmembers 376 that penetrate into the plunger 125 of the medicinecartridge 120 and thereby secure the medicine cartridge 120 to thepiston rod 170. (It should be understood that FIG. 9 depicts the pistonrod 370 arranged in the pump housing 110 of the pump device 100, andFIG. 10 shows a similar view with the pump housing 110 and otherportions removed for purposes of illustrating the piston rod 370 andmedicine cartridge 120.)

As shown in FIG. 9, the pump device 100 may include a drive system 300that is controlled by the removable controller device 200 (FIGS. 1-2).Accordingly, the drive system 105 can accurately and incrementallydispense fluid from the pump device 100 in a controlled manner. Thedrive system 300 may include the flexible piston rod 370 that isincrementally advanced toward the medicine cartridge 120 so as todispense the medicine from the pump device 100. In this embodiment, atleast a portion of the drive system 300 is mounted to the pump housing110, and a detachable shell 112 covers at least a portion of the drivesystem 105. The detachable shell 112 may include an inner curved surfaceagainst which a curved section of a piston rod 370 rests. A cover mount113 may be assembled to the pump housing 110 to secure some componentsof the drive system 300 with the pump housing 110, and the “unused” orretracted portion of the piston rod 370 may rest in a channel defined inthe top of the cover mount 113. Some embodiments of the drive system 300may include a battery powered actuator (e.g., reversible motor 320 orthe like) that resets a ratchet mechanism 330, a spring device 350 thatprovides the driving force to the ratchet mechanism 330, and a drivewheel 360 that is rotated by the ratchet mechanism 330 to advance theflexible piston rod 370 toward the medicine cartridge 120. The operationof the drive system 300 is described in more detail below in connectionwith FIGS. 26-30. Previously incorporated U.S. patent application Ser.No. 11/522,560 describes further drive system configurations for use inan infusion pump device.

Referring to FIG. 10, in some embodiments, the flexible piston rod 370comprises a plurality of segments 372 serially connected by hingeportions 373 so that the flexible piston rod 370 is adjustable from acurved shape to a noncurved shape. The plurality of segments 372 and theinterconnecting hinge portions 373 can be integrally formed in one piecefrom one or more moldable materials, including polymer materials such asNylon or POM. In this embodiment, each of the plurality of rod segments372 includes an exterior thread pattern 374 along at least onecylindrical surface portion. The plunger engagement device 375 can bearranged at a forward end of the piston rod 370. As such, the plungerengagement device 375 faces toward the medicine cartridge 120 when themedicine cartridge 120 is inserted into the cavity 116.

The plunger engagement device 375 is configured to attach to the plunger125 of the medicine cartridge 120 when urged together. For example, aspreviously described in connection with FIG. 7B, a longitudinal force140 may be applied to the medicine cartridge 120 during engagement ofthe cap device 130 to the pump housing 110. This longitudinal force 140can be used to urge the medicine cartridge 120 (and the plunger 125therein) toward the plunger engagement device 375. In this embodiment,the plunger engagement device 375 includes a plurality of penetrationmembers 376 that extend from a pusher disc 378 toward the plunger 125and are configured to penetrate into the plunger 125 in response to thelongitudinal force 140 (FIGS. 7B and 10). Thereafter, the plunger 125may remain secured to the piston rod 370 during operation of the pumpdevice 100.

Referring to FIGS. 11-12, in some embodiments, the penetration members376 may comprise rigid blades having pointed tips to pierce into therear face of the plunger 120 (e.g., the “dry” face of the plunger 125opposite the “wet” face). The penetration members 376 may extend for alength that is slightly less than the axial length of the plunger 125.In such circumstances, the penetration members 376 do not penetratethrough the front face (e.g., the “wet” face) of the plunger 125. Therigid blades may include serrations or another retention portion thatenhances the engagement with the plunger 125 and hinders separation ofthe plunger 125 from the penetration members 376. Also, in thisembodiment, the pusher disc 378 includes a protruding spherical surface379 that is configured to press against the rear face of the plunger 125(FIG. 12). In some circumstances, the center core of the plunger 125 maybe urged forward more than the radial surfaces of the plunger 125 (dueto the frictional engagement with the inner wall of the medicinecartridge 120). Accordingly, the protruding surface 379 of the disc 378may promote full contact with the rear face of the plunger 125 duringadvancement of the plunger 125 within the cartridge 120.

In some embodiments, the penetration members 376 can reduce thecompliance of the plunger material and thereby increase the dosageaccuracy. For example, the plunger 125 may comprise an elastomermaterial that exhibits flexibility and compliance when it is urgedlongitudinally relative to the inner wall of the medicine cartridge 120(e.g., the center of the plunger is urged forward while the outer radialsurfaces flex due to the frictional engagement with the inner wall ofthe medicine cartridge). Such compliance may create a level ofunpredictability between the piston rod movement and the correspondingplunger movement. The penetration members 376 can pierce into theplunger 125 and thereby serve as generally rigid inserts that reduce thecompliance exhibit by the plunger 125. In some circumstances, thepenetration members 376 can serve as inserts that provide greateruniformity between the piston rod movement and the corresponding plungermovement. As such, the pump device 100 may have increased accuracy forthe dosage of medicine that is dispensed in response to an incrementalmovement of the piston rod 370.

Furthermore, the penetration members 376 can reduce the likelihood ofaccidental medicine delivery when the pump device 100 undergoes animpact (e.g., when the pump device is dropped on the ground). Thepenetration members 376 secure the plunger 125 to the drive system(e.g., to the piston rod 370 in this embodiment), so the plunger 125does not necessarily become displaced when the medicine cartridge 120 isimpacted. For example, if the pump device 100 is dropped on the groundand undergoes an impact, the plunger 125 may be retained in its positionrelative to the wall of the cartridge due to the attachment with thepiston rod 370. As such, the likelihood of the plunger 125 movingslightly relative to the inner wall of the medicine cartridge 120 (andthereby forcing some medicine from the cartridge) in response to animpact may be reduced.

It should be understood from the description herein that, in someembodiments, the penetration members 376 can reduce the compliance ofthe plunger 125 so that the pusher disc 378 need not include aprotruding spherical surface (e.g., surface 379 in FIG. 12). Rather, thepusher disc 376 may include a generally flat surface that pushes againstthe rear face of the plunger 125 (as shown, for example, in FIGS.13A-D).

Referring to FIGS. 13A-D, in operation, the plunger engagement device375 can be secured to the plunger 125 to reduce or prevent relativemotion between the plunger 125 and the pusher disc 378 and to reduce thecompliance of the plunger 125. As previously described in connectionwith FIG. 7B and FIG. 10, a longitudinal force 140 may be applied to themedicine cartridge 120 during engagement of the cap device 130 to thepump housing 110. This longitudinal force 140 is used to urge themedicine cartridge 120 (and the plunger 125 therein) toward thepenetration members 376 of the plunger engagement device 375. As theplunger 125 continues its motion toward the pusher disc 378 in responseto the longitudinal force 140, the penetration members 376 can pierceinto the rear face of the plunger 125. The insertion of the penetrationmembers 376 may continue until the rear face of the plunger 125 abutsthe pusher disc 378. As shown in FIG. 13D, the penetration members 376do not penetrate through the front face (e.g., the “wet” face) of theplunger 125 in this embodiment.

In this embodiment, the plunger engagement device 375 includes threepenetration members 376 that are laterally offset from the center of thepusher disc 378. The penetration members 376 comprise rigid blades orknife-like pins that include serrations to facilitate engagement withthe plunger 125. These rigid blades may be laterally offset from thecenter of the pusher disc 378 so as to pierce the rear face of theplunger 125 in an outer radial portion of the plunger 125 (e.g., aportion of the plunger that might otherwise be more compliant duringadvancement of the plunger 125 inside the cartridge 120).

It should be understood from the description herein that, in otherembodiments, the plunger engagement device 375 may have a differentconfiguration. For example, as shown in FIGS. 14A-B, some embodiments ofthe plunger engagement device 375 may include penetration members 382 inthe form of pin inserts. These penetration members 382 can include agenerally straight shaft and pointed tip to facilitate penetration intothe rear face of the plunger 125 (FIG. 14B). In another example, asshown in FIGS. 15A-B, some embodiments of the plunger engagement device375 may include penetration members 384 in the form of radially curvedblades. Such embodiments of the penetration members 384 may includegenerally flat blade shafts that are curved about a longitudinal axis.The radial curvature of the penetration members 384 may reflect theradial distance from the central longitudinal axis of the plunger 125(FIG. 15B). In yet another example, as shown in FIGS. 16A-B, someembodiments of the plunger engagement device 375 may include penetrationmembers 386 in the form of generally flat blades without serrations.These penetration members 386 may include a pointed tip to facilitateinsertion into the plunger 125 (FIG. 16B). In a further example, theplunger engagement device 375 may include an adhesive layer arranged onthe pusher disc 378 so that the pusher disc 378 becomes adhered to therear face of the plunger 125.

In some embodiments in which the plunger engagement device 375 includespenetration members having serrations or other retention portions, theretention portions may be formed in a number of configurations. Forexample, as shown in FIG. 17, some embodiments of the plunger engagementdevice 375 may include penetration members 387 having straight-cutretention portions that hinder separation of the plunger 125 away fromthe plunger engagement device 375. In another example, as shown in FIG.18, some embodiments of the plunger engagement device 375 may includepenetration members 388 having angled-cut retention portions.

Some embodiments of the plunger engagement device 375 may include onepenetration member, two penetration members, three penetration members(as previously described in connection with FIGS. 11-12 and 13A-D), fourpenetration members, five penetration members, or more. Moreover, thepenetration members may be arranged on the plunger engagement device 375in a number of different configurations so as to penetrate the plunger125 at different locations. For example, as shown in FIG. 19, someembodiments of the plunger engagement device 375 may include only onepenetration member (depicted here in the form of a pin insertpenetration member 382 described in FIGS. 14A-B). In this embodiment,the single penetration member 382 is arranged to pierce the rear face ofthe plunger 125 proximate to the central axis of the plunger 125. Inanother example, as shown in FIG. 20, some embodiments of the plungerengagement device 375 may include two penetration members (again,depicted here in the form of a pin insert penetration member 382described in FIGS. 14A-B). In this embodiment, the pair of penetrationmembers 382 are offset from the central axis of the plunger 125 andoriented approximately 180° from one another. As such, the penetrationmembers 382 can pierce into the rear face of the plunger 125 ongenerally opposite sides of the central axis of the plunger 125. In afurther example, as shown in FIG. 21, some embodiments of the plungerengagement device 375 may include four penetration members 382 that areoffset from the central axis of the plunger 125 and orientedapproximately 90° from one another. In yet another example, as shown inFIG. 21, some embodiments of the plunger engagement device 375 mayinclude five penetration members 382 that are offset from the centralaxis of the plunger 125 and oriented approximately 72° from one another.

Some embodiments of the plunger engagement device 375 may includepenetration members that are not oriented circumferentially equidistantto one another. For example, as shown in FIG. 23, some embodiments ofthe plunger engagement device 375 may include four penetration members382 that are spaced apart in two pairs. A first pair of the penetrationmembers 382 are spaced apart from the second pair of penetration members382. As such, the first and second pairs of the penetration members 382can pierce into the rear face of the plunger 125 on generally oppositesides of the central axis of the plunger 125.

Also, some embodiments of the plunger engagement device 375 may includecombinations of the previously described configurations. For example, asshown in FIG. 24, some embodiments of the plunger engagement device 375may include a first penetration member 382 arranged to pierce the rearface of the plunger 125 proximate to the central axis of the plunger 125(similar to that shown in FIG. 19) and four addition penetration members382 that are offset from the central axis of the plunger 125 andoriented approximately 90° from one another (similar to those shown inFIG. 21).

Some embodiments of the piston rod 370 may include a plunger engagementdevice 380 that penetrates along the outer circumferential surface ofthe plunger 125. For example, as shown in FIG. 25, the plungerengagement device 380 may include a cylindrical penetration member 381that is integral with the pusher disc portion. The cylindricalpenetration member 381 can penetrate along the outer circumferentialsurface of the plunger 125 (e.g., through the outer rings of the plunger125 or between the outer rings and the cartridge wall) when the plunger125 is urged toward the piston rod 370. In this example, the cylindricalpenetration member 381 bypasses the first two outer rings of the plunger125 so that at least a portion of the load on the third ring is directlytransmitted to the plunger engagement device 380. As such, the plungerengagement device 380 can be used to retain the plunger 125 relative tothe piston rod 370 and to reduce the compliance of the plunger 125 whenbeing advanced inside the medicine cartridge 120.

Referring now to FIGS. 26-30, the drive system 300 of the pump devicecan be controlled to accurately dispense fluid from the pump device 100.As previously described in connection with FIGS. 9-10, the drive system300 may include the flexible piston rod 370 that is incrementallyadvanced toward the medicine cartridge 120 so as to dispense themedicine from the pump device 100. The drive system 300 may also includean electrically powered actuator (e.g., reversible motor 320 or thelike) that is coupled to a guided pusher arm 325 (FIGS. 28-30), which isused to adjust a ratchet mechanism 330 to a reset position. A springdevice 350 (FIGS. 28-30) stores potential energy when the ratchetmechanism 330 is adjusted to the reset position and thereafter drivesthe ratchet mechanism 330 to a forward position to advance the pistonrod 370 and dispense the medicine. The motor 320 can be decoupled fromthe ratchet mechanism 330 during the drive step. Accordingly, thereversible motor 320 is used to shift the ratchet mechanism to a resetposition, but the motor 320 does not drive the ratchet mechanism 330 tothe forward position.

In those embodiments in which the pump device 100 is connected to aremovable controller device 200 (FIGS. 1-2), the controller device 200can communicate control signals to the drive system 300 or othercomponents of the pump device 100. As previously described, thecontroller device 200 can include a controller housing structure 210(FIGS. 1-2) that is configured to mate with a complementary portion ofthe pump housing structure 110 so as to form a mechanical connection. Insuch circumstances, the pump device 100 may include on or moreelectrical contacts 118 (FIG. 26) that are exposed to the controllerdevice 200 and that mate with opposing electrical contacts (e.g., pads,pins, or the like) on the adjacent face of the controller device 200. Inthis embodiment, the electrical contacts 118 are disposed on aconnection circuit 119 (FIG. 26). The connection circuit 119 may besimple and inexpensive so as to facilitate a low-cost pump device 100that is disposable. The connection circuit 119 can be in electricalcommunication with one or more components housed in the pump device 100,such as the motor 320, the battery 305, one or more sensor devices, or acombination thereof). The connection circuit 119 facilitates electricalcommunication with the removable controller device 200 (FIGS. 1-2). Assuch, the controller device 200 is capable of transmitting electricalsignals to the pump device 100 and is capable of receiving feedbacksignals (e.g., sensor signals) from the components in the pump device100.

As shown in FIG. 26, some components of the drive system 300 can beretained by the pump housing 110. For example, the motor 320, the pusherarm 325, the ratchet mechanism 330, and the spring device 350 can beassembled into the pump housing 110 and then retained by the cover mount113 (FIG. 9). Also, the drive wheel 360 and an adjacent bearing 365 (tofacilitate rotation of the drive wheel 360 relative to the pump housing110) can be received in annular channels of the pump housing 110. Inthis embodiment, a locking pawl 342 (FIGS. 28-30) is integrally formedwith the pump housing 110 so as to align with a portion of the ratchetmechanism 330 when the ratchet mechanism 330 is assembled onto the pumphousing 110. When the cover mount 113 (FIG. 9) is assembled to the pumphousing 110, the cover mount 113 can align and retain the ratchetmechanism 330 and other components of the drive system 300. In such aconstruction, the assembled pump housing 110 can permit the desiredmotion of the components of the drive system 300 while reducing thelikelihood of “backlash” movement or component dislodgement (which mightotherwise occur, for example, when the pump device 100 is dropped to theground).

Referring to FIGS. 27-30, in some embodiments of the drive system 300,the reversible motor 320 is used to shift the ratchet mechanism 330 tothe reset position, yet the motor 320 can be decoupled from the ratchetmechanism 330 during the drive step that causes dispensation ofmedicine. Briefly, the motor 320 can be used to act upon the pusher arm325, which is guided along a predetermined path in a guide slot 328. Inthis embodiment, the guide slot 328 is integrally formed in an innerwall of the pump housing 110 (refer to FIG. 26), and the pusher arm 325includes a slider pin 326 that mates with the guide slot 328. (It shouldbe understood that FIG. 26 depicts the drive system 300 mounted to thepump housing 110 of the pump device 100, and FIG. 27 shows a similarview with the pump housing 110 removed for purposes of illustratingcomponents of the drive system 300.) After the pusher arm 325 isadvanced in the guide slot 328 so that the ratchet mechanism 330 isadjusted to the reset position (refer to FIG. 29 in which the ratchetmechanism 330 is reset to engage a new tooth on the ratchet body 340),the motor 320 can reverse direction and promptly retract the pusher arm325 to the first position (refer to FIG. 30 in which the pusher arm 325is retracted). The spring device 350 provides the energy for the drivestep that advances the piston rod 370 and dispenses medicine, but thedrive step may occur over a period of time that is greater than therelatively quick retraction of the pusher arm 325 to the first position.In such circumstances, the pusher arm 325 may be temporarily separatedfrom the ratchet mechanism 330, thereby causing the motor to bedecoupled from the ratchet mechanism 330 during the drive step.Accordingly, the drive system 300 can provide an efficient process foraccurately and reliably dispensing medicine in a manner that conservesbattery life. Moreover, the drive system 300 may comprise few, if any,high-cost actuator components or electronics, thereby facilitating theproduction of a disposable and reliable pump device 100.

Referring now in more detail to the components of the drive system 300depicted in FIGS. 27-30, the electrically power actuator may be in theform of the motor 320 having a rotatable output shaft 321. In thisembodiment, the motor 320 is reversible in that can receive signals thatcause the output shaft 321 to rotate in a first rotational direction orin a second, opposite rotational direction. One example of a suitablemotor 320 is a coreless DC motor with reversible rotation capabilities,as supplied by Mabuchi Motor Co. of Japan. As previously described, theoperation of the motor 320 can be controlled by a control device (e.g.,removable control device 200 as described in connection with FIGS. 1-2or the like) via electrical signals communicated through one or moreelectrical contacts.

Still referring to FIGS. 27-30, a gear system 322 may be coupled to themotor 320 so that actuation by the motor 320 causes the pusher arm 325to act upon the ratchet mechanism 330 or to decouple from the ratchetmechanism 330. In this embodiment, the gear system 322 includes a wormgear 323 and a gear reduction assembly comprising spur gears 324 a, 324b, and 324 c. The pusher arm 325 can be pivotably coupled to the gear324 c so that partial rotation of the gear 324 c causes the pusher armto reciprocate within the guide slot 328. Accordingly, rotation of themotor 320 in a first direction can be translated into an advancementforce to the pusher arm 325. The advancement force on the pusher arm 325is applied to a pawl member 335, which (in this embodiment) causes thepawl member 335 to pivot to a reset position (refer to FIG. 29). Inaddition, rotation of the motor 320 in a second direction can betranslated into an retraction force to the pusher arm 325, which cancause the pusher arm 325 to be separated from the pawl member 335 duringthe drive step (refer to FIG. 30).

As such, the motor 320, the gear system 322, and the pusher arm 325 cancollectively operate as an actuator assembly that provides a reliableand consistent adjustment of the ratchet mechanism 330 during a resetstep (refer to FIG. 29). Moreover, this actuator assembly (e.g., themotor 320, the gear system 322, and the pusher arm 325) can be activatedto separate from the pawl member 335, thereby permitting the motor 320to decouple from the ratchet mechanism 330 during a drive step (refer toFIG. 30).

The motion path of the pusher arm 325 can be configured to provide anefficient mechanical advantage orientation during the desired motion ofthe adjustable pawl member 335. In this embodiment, the pusher arm 325is directed by a guide slot 328 formed in the pump housing 110 (FIG.26). In particular, the pusher arm 325 includes the slider pin 326 thatis received within the guide slot 328 during assembly. The portion ofthe pusher arm 325 proximate the slider pin 326 can abut against thepawl member 335 when the pusher arm is advanced. As such, when a firstend of the pusher arm 325 is moved by the gear 324 c, a second end ofthe pusher arm (proximate the slider pin 326) is directed by the guideslot 328. The orientation of the pusher arm 325 relative to the guideslot 328 can be configured to provide an efficient mechanical advantagefor the pushing force applied by the pusher arm 325 during the desiredmotion of the adjustable pawl member 335.

Still referring to FIGS. 27-30, the ratchet mechanism 330 includes thepawl member 335 and a ratchet body 340, which in this embodiment is aratchet wheel having a number of teeth along its circumferentialsurface. In this embodiment, the ratchet wheel 340 is coupled with aworm gear 345, and incremental rotation of the ratchet wheel 340 causesrotation of a drive wheel 360 (due to engagement with the worm gear345). The pawl member 335 is adjustable between a reset position (referto FIG. 29) and a forward position (refer to FIG. 28). For example,during the reset step, the motor 320 may be activated to advance thepusher arm 325 (guided by the guide slot 328), and the pusher arm 325then applies a pushing force that adjusts the pawl member 335 to thereset position in which the pawl member 335 grabs a new tooth of theratchet wheel 340 (refer to FIG. 29). In this embodiment, the adjustablepawl member 335 is pivotably coupled to about the axis of an axle 332(refer to FIG. 26) that receives the ratchet wheel 340 and the worm gear345.

A spring device 350 is also coupled to the pawl member 335 so as to urgethe pawl member 335 toward the forward position (refer to FIG. 28). Inthis embodiment, the spring device 350 is in the form of a coil springthat is fixed to the pump housing 110 (not shown in FIGS. 27-30) at afirst end portion 352 and that is engaged with the pawl member 335 at asecond end portion 354. Thus, as shown in FIG. 29, when the pawl member335 is adjusted to the reset position, the spring device 350 is intension and stores potential energy that urges the pawl member 335 toreturn to the forward position (refer to FIG. 28) and thereby drive theratchet wheel 340 in a forward rotational direction. As previouslydescribed, a locking pawl 342 (FIGS. 28-30) can be used to prevent theratchet wheel 340 from reverse motion. The locking pawl 342 can flex orotherwise adjust to permit the incremental forward rotation of theratchet wheel 340. As such, the adjustable pawl member 335 can adjustfrom the forward position (refer to FIG. 28) to the reset position(refer to FIG. 29) to engage a new tooth of the ratchet wheel 340 whilethe ratchet wheel 340 remains in position due to the locking pawl 342.

It should be understood that the drive system 300 can employ a set oflocation sensors to indicate when the pawl member 335 has reach thereset position or the forward position. For example, these sensors canbe optical, magnetic, or contact-type sensors. The sensors may becapable of transmitting signals that indicate when the location of oneof the gears in the gear system 322, the pusher arm 325, or the pawlmember 335 is detected. Such sensor signals may be transmitted to themotor 330, to the controller device 200 (FIGS. 1-2), or a combinationthereof. In one embodiment, the pawl member 335 may be equipped with anelectrically conductive contact that engages a first contact-type sensorwhen moved to the reset position and that engages a second contact-typesensor when moved to the forward position. As such, the first and secondcontact-type sensors can electrically communicate with the motor 330,the controller device 200, or both when the pawl member reaches thereset and forward positions. These signals may be used to indicate whenthe motor 330 should cease rotation or reverse rotation.

Still referring to FIGS. 27-30, in some embodiments the ratchet wheel340 can be integrally formed with the worm gear 345 so that theincremental rotation of the ratchet wheel 340 is translated to the wormgear 345. Such rotation of the worm gear 345 causes rotation of thedrive wheel 360. The drive wheel 360 includes a central aperture havingan internal thread pattern therein (not shown in FIGS. 27-30), whichmates is an external thread pattern 374 on the rod segments 372. Thus,the incremental motion provided by the ratchet mechanism 330, the pusherarm 325, and the motor 320 causes the drive wheel 360 to incrementallyrotate, which in turn translates to a longitudinal advancement of theflexible piston rod 370.

Accordingly, in some embodiments, the piston rod 370 may undergo onlyforward or positive longitudinal displacement as a result of drivesystem 300. For example, the drive system 300 substantially hinders thepiston rod 370 from retracting or “backing up” in response to fluidpressure in the medicine cartridge 120 or other reversal forces. In suchcircumstances, the flexible piston rod 370 can be retracted only upondisassembly of the pump device 300 (e.g., to disengage the drive gear360 or the ratchet mechanism 330). In those embodiments in which thepump device 100 is intended to be disposable, the non-retractable pistonrod configuration may facilitate a “one time use” disposable pumpdevice, thereby reducing the likelihood of failure due to non-intendedrepeated use of the disposable pump device 100.

Still referring to FIGS. 27-30, the flexible piston rod 370 can comprisea plurality of rod segments 372 serially connected by hinge portions 373so that the flexible piston rod 370 is adjustable from a curved shape toa noncurved shape. As previously described, the plurality of segments372 and the interconnecting hinge portions can be integrally formed inone piece from one or more moldable materials, including a number ofpolymer materials. In this embodiment, the plurality of segments 372comprise generally cylindrical segments that have an exterior threadpattern 374 along at least one cylindrical surface portion. Aspreviously described, the plunger engagement device 375 can be arrangedat a forward end of the piston rod 370 so that the plunger engagementdevice 375 faces toward the medicine cartridge 120.

In some embodiments, the flexible piston rod 370 can include ananti-rotation structure that hinders the piston rod 370 from rotatingwith the drive wheel 360 (thereby allowing the rotation of the drivewheel 360 to translate into a longitudinal motion of the piston rod370). For example, in this embodiment, the flexible piston 370 includeslongitudinal flat surfaces 371 extending along each of the segments 372.The longitudinal flat surfaces 371 can engage a complementary surface onthe pump housing 110 (not shown in FIGS. 27-30) proximate the drivewheel 360 so that the flexible piston rod 370 is hindered from rotatingwhen the drive wheel 360 turns. Accordingly, the longitudinal flatsurfaces 371 on each segment 372 aligns to form a keyway that receives amating key (e.g., a complementary flat surface) on the pump housing. Inother embodiments, the anti-rotation structure may include one or morelongitudinal channels 173 (with each channel capable of engaging anassociated protrusion that acts as a key to hinder rotation whilepermitting longitudinal motion) or the like. Previously incorporatedU.S. patent application Ser. No. 11/522,836 describes further piston rodconfigurations for use in an infusion pump device.

Because the flexible piston rod 370 is adjustable from a curved shape toa noncurved shape, the overall length of the pump device can be reducedin some embodiments. For example, in a typical infusion pump that housesa straight and rigid rod, the typical infusion pump requires a packageor housing having a linear dimension sufficient to accommodate thelength of the rigid piston rod when it is at its limit of travel inwhich it is fully withdrawn from the container or cylinder. The pumpdevice 100 incorporating the flexible piston rod 370 can require lessspace than a similar device that houses a non-flexible, rigid rod.

Referring now to FIGS. 28-30, the incremental motion cycle of the drivesystem 300 may include rotation of the motor 320 so that the pusher arm325 is advanced from a first position to act upon the pawl member 335and then retracted back to the first position. Such movement of thepusher arm 325 can cause the pawl member 335 to adjust from the forwardposition (refer to FIG. 28), to the reset position (refer to FIG. 29),and back to the forward position (under the driving force of the springdevice 350). The adjustment of the pawl member 352 from the resetposition to the forward position drives the ratchet wheel 340 and wormgear 345, which incrementally rotates the drive wheel 360 and therebyadvances the flexible piston rod 370 a longitudinal increment distance.In one example, the drive system 300 can advance the piston rod 370 alongitudinal increment distance of about 16 microns or less (about 4microns to about 12 microns, about 5 microns to about 9 microns, andpreferably about 6 microns to about 8 microns) for each incrementalmotion cycle of the ratchet mechanism 330.

Referring to FIG. 28, in this embodiment of the incremental motioncycle, the pawl member 335 begins at the forward position with thepusher arm 325 refracted in a first position (e.g., the rest position inthis embodiment). The adjustable pawl member 335 can be in this forwardposition, for example, because the drive system 300 previously completeda drive step at an earlier time.

Referring to FIG. 29, in response to the controller device transmittinga signal to initiate the cycle, the motor 320 may begin to rotate in afirst rotational direction that advances the pusher arm 325 to pushagainst the pawl member 335. Such movement of the pusher arm 325 causesa pushing force 327 that overcomes the bias of the spring device 350 andadjusts the pawl member 335 toward the reset position (e.g., the resetstep). When the adjustable pawl member 335 reaches the reset position,as shown in FIG. 29, the pawl member 335 is capable of engaging a newtooth of the ratchet wheel 340. The locking pawl 342 prevents theratchet wheel 340 from rotating in a reverse (non-forward) rotationaldirection while the adjustable pawl member 335 is shifting back to thereset position. Such an adjustment of the pawl member 335 back to thereset position creates a tension force 357 in the spring device 350 (asshown in FIG. 29), thereby storing potential energy to drive theadjustable pawl member 335 and ratchet wheel 340 in a forward rotationaldirection for the drive step.

Referring to FIG. 30, after the pawl member 335 reaches the resetposition, the motor 330 stops rotating in the first rotational directionand reverses to rotate in the second, opposite rotational direction.Such rotation in the second direction by the motor 320 causes the pusherarm 325 to promptly retract to the first position (while guided by theguide slot 328). As such, the spring device 350 begins to urge the pawlmember 335 toward the forward position. When the adjustable pawl 335 isdriving the ratchet wheel 340 in the forward rotational direction, thepotential energy of the spring device 350 is being translated to kineticenergy for the motion of the pawl member 335 and the ratchet wheel 340.Such an adjustment of the pawl member 335 from the reset position to theforward position drives the ratchet wheel 340 and the integrally formedworm gear 345. The incremental rotation of the worm gear 345 results inan incremental rotation by the drive wheel 360, which advances theflexible piston rod 370 a longitudinal increment distance. Such anincremental advancement of the flexible piston rod 370 can cause apredetermined volume of fluid to be dispensed from the cartridge 120. Inthe event of a subsequent cycle (including the reset step and the drivestep), the motor 320 would begin by rotating in the first rotationaldirection so as to advance the pusher arm 325 yet again. This pattern ofcycles may continue until the piston rod 370 has reached the limit ofits longitudinal travel.

Still referring to FIG. 30, although the pusher arm 325 can be promptlyretracted to the first position due to the reverse rotation of the motor320, the pawl member 335 is driven to the forward position (FIG. 28)over a greater period of time. This period of time required for thedrive step is affected by a number of factors, including the springforce from the spring device 350, the fluid pressure inside the medicinecartridge 120, and the like. Accordingly, the pusher arm 325 can betemporarily separated from the pawl member 335 when it is retracted toits first position, thereby causing the motor 320 to be decoupled fromthe ratchet mechanism 330 during the drive step. For example, theportion of the pusher arm 325 proximate the slider pin 326 can becometemporarily spaced apart by a distance 329 from the pawl member 335while the pawl member 335 is being driven from the reset position (FIG.29) to the forward position (FIG. 28). Such a configuration permits themotor 320 to expend a short burst of electrical energy to reset theratchet mechanism 330 (e.g., during advancement of the pusher arm 325)while contributing no energy during the drive step to drive the ratchetmechanism 330 to the forward position for dispensation of medicine.Because the motor 320 can be decoupled from the ratchet mechanism 330during the drive step, only the spring device 350 expends energy over aperiod of time to drive the ratchet mechanism 330 to the forwardposition. Accordingly, the pump device 100 can reliably and accuratelydispense dosages of medicine in a safe and energy efficient manner. Inparticular, the motor 320 is not required to draw energy from thebattery over an extended period of time (e.g., during the drive step inwhich the piston rod 370 is advanced to dispense medicine over a periodof time). Instead, the motor 320 may draw upon the battery power duringadvancement of the pusher arm 325 to quickly reset the ratchet mechanism330 and during the brief retraction of the pusher arm 325.

A number of embodiments of the invention have been described.Nevertheless, it will be understood that various modifications may bemade without departing from the spirit and scope of the invention.Accordingly, other embodiments are within the scope of the followingclaims.

What is claimed is:
 1. An infusion pump device, comprising: a pumphousing that defines a space to receive a medicine; a drive system todispense a medicine from the pump housing when the medicine is receivedin the space, the drive system comprising: a ratchet mechanism thatadvances a piston rod during a drive step to dispense the medicine whenthe medicine is received in the space; and an electrically poweredactuator that decouples from the ratchet mechanism during the drivestep.
 2. The infusion pump device of claim 1, wherein the electricallypowered actuator of drive system comprises a rotational motor thatdecouples from the ratchet mechanism during the drive step in which thepiston rod is advanced and that couples with the ratchet mechanism toprovide a reset force to the ratchet mechanism.
 3. The infusion pumpdevice of claim 1, wherein the drive system further comprises a springdevice that provides a drive force to the ratchet mechanism during thedrive step to advance the ratchet mechanism in a forward direction. 4.The infusion pump device of claim 3, wherein the electrically poweredactuator is coupled to the ratchet mechanism during a reset cycle toprovide a reset force to the ratchet mechanism.
 5. The infusion pumpdevice of claim 4, wherein the electrically powered actuator expendselectrical energy for a first period of time to reset the ratchetmechanism and expends no electrical energy for generating a force uponthe ratchet mechanism when the spring device advances the ratchetmechanism in the forward direction.
 6. The infusion pump device of claim1, wherein the electrically powered actuator comprises a bi-directionalactuator.
 7. The infusion pump device of claim 5, wherein theelectrically powered actuator comprises a reversible rotational motor.8. The infusion pump device of claim 1, wherein the drive system furthercomprises a pusher member coupled to the electrically powered actuator,wherein the electrically powered actuator decouples from the ratchetmechanism by the pusher member shifting away from abutment with theratchet mechanism to separate from the ratchet mechanism.
 9. Theinfusion pump device of claim 8, wherein the pusher member is advancedand retracted by the electrically powered actuator, and at least aportion of the pusher member movement is directed by a guide slot. 10.The infusion pump device of claim 8, wherein the pusher member iscoupled to the electrically powered actuator via one or more gears. 11.The infusion pump device of claim 1, wherein an interior wall definingthe space in the pump housing is configured to slidably receive aprefilled medicine cartridge through an exterior opening on the pumphousing.
 12. The infusion pump device of claim 11, wherein the pistonrod includes a plunger engagement device that attaches to a plunger ofthe medicine cartridge when the medicine cartridge is received by thepump housing.
 13. The infusion pump device of claim 11, furthercomprising a cap device that engages the pump housing to cover saidexterior opening and retain the medicine cartridge therein when themedicine cartridge is received by the pump housing, wherein when the capdevice engages the pump housing, the cap device acts upon the medicinecartridge to urge the plunger into attachment with the plungerengagement device of the piston rod.
 14. The infusion device of claim13, wherein the plunger engagement device comprises one or morepenetration members that pierce into a first side of the plunger duringattachment of the plunger and the plunger engagement device.
 15. Theinfusion pump device of claim 11, further comprising one or more lockingelements that adjust to a locked position relative to the pump housingwhen the medicine cartridge is fully received in the space of the pumphousing, wherein said one or more locking elements hinder removal of themedicine cartridge from the pump housing when the medicine cartridge isfully received in the space of the pump housing.
 16. The infusion pumpdevice of claim 15, wherein said one or more locking elements preventreuse of a new medicine cartridge in the pump housing after the medicinecartridge is fully received in the space of the pump housing.
 17. Theinfusion pump device of claim 16, wherein said one or more lockingelements and the pump housing configure the infusion pump device as asingle-use, disposable unit.